Alternative transportation fuels have been represented as enablers to reduce toxic emissions in comparison to those generated by conventional fuels. At the same time, tighter emission standards and significant innovation in catalyst formulations and engine controls has led to dramatic improvements in the low emission performance and robustness of gasoline and diesel engine systems.
One approach to addressing the issue of emissions is the employment of fuel cells, particularly solid oxide fuel cells (xe2x80x9cSOFCxe2x80x9d), in a transportation vehicle. A fuel cell is an energy conversion device that converts chemical energy into electrical energy. The fuel cell generates electricity and heat by electrochemically combining a gaseous fuel, such as hydrogen, carbon monoxide, or a hydrocarbon, and an oxidant, such as air or oxygen, across an ion-conducting electrolyte. The fuel cell generally consists of two electrodes positioned on opposite sides of an electrolyte. The oxidant passes over the oxygen electrode (cathode) while the fuel passes over the fuel electrode (anode), generating electricity, water, and heat.
A SOFC is constructed entirely of solid-state materials, utilizing an ion conductive oxide ceramic as the electrolyte. The electrochemical cell in a SOFC comprises an anode and a cathode with an electrolyte disposed therebetween.
Application and research efforts during the 20th century into using SOFCs were generally concentrated in the stationary power generation industry. Because of those SOFC designs, the SOFC was not readily adaptable for use in a transportation vehicle. A transportation vehicle application imposes specific temperature, volume, and mass requirements, as well as real world factors, such as fuel infrastructure, government regulations, and cost.
Characterizing the output of the reformer and the SOFC stack are indicators of how well the overall SOFC system is performing. It is important to know the constituents and their proportions in the gas streams entering and exiting the SOFC stack. These gas streams are located in a high temperature environment (i.e., about 600xc2x0 C. to 1,000xc2x0 C.). Completing monitoring of the constituents and their proportions with conventional sensors is not feasible, since most sensors operate in environments with temperatures of less than 100xc2x0 C., and with a gas stream temperature of less than 100xc2x0 C.
The drawbacks and disadvantages of the prior art are overcome by the solid oxide fuel cell process gas sampling.
A method for monitoring process gas of a solid oxide fuel cell system is disclosed. The method comprises directing a portion of process gas from a chamber of the solid oxide fuel cell system to a main plenum chamber. A portion of process gas is cooled to a measurable temperature and directed to a sensor for analyzing.
A method for monitoring reformate of a solid oxide fuel cell system is disclosed. The method comprises directing a portion of reformate from a chamber of the solid oxide fuel cell system to a main plenum chamber. A portion of reformate is cooled to a measurable temperature and directed to a sensor for analyzing. A signal is relayed from the sensor to a controller. The cooled portion of reformats is eliminated from the solid oxide fuel cell system.
A solid oxide fuel cell system is disclosed. The system comprises a chamber disposed around a solid oxide fuel cell stack and a waste energy recovery assembly. A means for diverting a portion of process gas contained within the chamber is in fluid communication with a means for cooling the diverted portion of process gas to a measurable temperature. The system also comprises a means for analyzing the cooled portion of process gas.
A solid oxide fuel cell system is disclosed. The system comprises a chamber disposed within the solid oxide fuel cell system. A means for diverting a portion of process gas contained within the chamber is in fluid communication with a means for cooling the diverted portion of process gas to a measurable temperature. The system also comprises a means for analyzing the cooled portion of process gas and a means for directing the cooled portion of process gas out of the solid oxide fuel cell system.
The above described and other features are exemplified by the following figures and detailed description.